It’s hard to find the right module on the market with more than 700 manufacturers offering more than several thousand module types.
Apart from size, solar photovoltaic modules all look the same and you cannot tell their quality. The difference between good and poor quality modules reveal themselves only over time. If your investing in solar power then a modules long term stability is the goal.
IEC Certification doesn’t tell the real story. It is only a minimum requirement.
Some solar photovoltaic manufacturers only submit “good modules” for certification, not necessarily from serial production. In such cases, certificates do not always tell us whether modules installed on roofs actually fulfil the minimum quality requirements.
If one panel on your roof is performing poorly this lowers the output of electricity from all the panels…
Inferior modules produce 5 % less electricity under low light conditions and 10% less at high temperatures.
Some module manufacturers claim their modules are “made with German technology”, although they are often from China. This can simply mean the supplier used machines and materials from Germany, but customers could easily misinterpret that the module was ‘made in Germany”.
Read what the industry experts look for in solar power modules….Read More from PV Magazine February 2011
In practice PV systems show considerable differences in energy yield even if their rated power is comparable. These differences originate from several factors notably the PV modules, inverter and the quality of the site installation. Further important aspects are among others a careful sizing of system components, a good overall system design and an optimised module orientation…..Read More from Schott Solar website